Devices and methods for treating sleep disordered breathing

ABSTRACT

Devices and methods of treating sleep disordered breathing are provided herein. The devices are designed capable of preventing collapse of an oral airway tissue during sleep while maintaining normal velopharyngeal functions.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/745,896 filed on Jun. 3, 2010, which is a National Phase of PCTPatent Application No. PCT/IL2008/001566 filed on Dec. 2, 2008, whichclaims the benefit of priority from U.S. Provisional Patent ApplicationNo. 60/996,790 filed Dec. 5, 2007.

The contents of all of the above documents are incorporated by referenceas if fully set forth herein.

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to devices and methods for treating sleepdisordered breathing and, more particularly, to devices which aredesigned for preventing collapse of airway tissue.

Snoring, excessive daytime somnolence, restless sleep, and obstructivesleep apnea (OSA) are manifestations of sleep-disordered breathing (SDB)which is characterized by abnormalities in respiratory patterns or thequantity of ventilation during sleep.

Obstructive sleep apnea, which is the most common SDB is caused by sleeptime collapse of airway tissue forming the pharyngeal wall, soft palate,epiglottis, and/or tongue.

Postural muscle tone is highest in wakefulness, decreased in non-REMsleep, and minimal or absent in REM sleep. Collapse of tissuesexperienced during REM sleep, leads to a cycle of air flow obstruction,disruption of sleep and arousal.

The recurrent sleep arousal and associated intermittent hypoxia andhypercapnia have been implicated in the occurrence of adversecardiovascular outcomes. In addition, there is evolving evidence thatSDB may contribute to insulin resistance and other components of themetabolic syndrome.

Numerous efforts have been made to treat sleep disordered breathing.These include uvulectomy, nasal reconstruction, adenotonsillectomy,uvulopalatopharyngoplasty (UPPP), genioglossal advancement as well asmore complex surgical approaches such as maxillary-mandibularadvancement, bimaxillary advancement, and tongue-base surgery.

The type of intervention selected for treatment is based largely onpatient physiology and anatomy. A patient with a large uvula who snoresand has few or no symptoms of apnea may benefit from uvulectomy or fromthe Pillar™ implant which is used to stiffen the soft palate.

Relief of nasal obstruction alone rarely cures OSA, however, patienttolerance and response to nasal CPAP are often improved, thusseptoplasty, septorhinoplasty, and turbinate reduction may be indicatedin patients who have predisposing anatomy.

Adenotonsillectomy is often performed in the pediatric population tocorrect loud snoring and restless sleep.

Uvulopalatopharyngoplasty (UPPP) is a procedure which is performed mostoften for treatment of OSA. This procedure includes of tonsillectomy,reorientation of the anterior and posterior tonsillar pillars, andexcision of the uvula and posterior rim of the soft palate.

Genioglossal advancement involves performing a mandibular osteotomy withanterior repositioning of the genioglossus-attached segment of themandible. This procedure results in anterior displacement of the tongue.

Lingual tonsillectomy, lingualplasty, and laser midline glossectomy areprocedures designed to reduce the mass of the tongue base.Temperature-controlled radiofrequency tissue ablation (TCRFTA) is usedto reduce tissue mass of the tongue base and in the soft palate.

Despite considerable progress in our understanding of these disordersand the development of numerous treatment options, the principaltherapeutic approach, continuous positive airway pressure (CPAP) whichhas been readily available since 1981 and exhibits poor patienttolerability and compliance remains the mainstay SDB treatment to thisday.

There is thus a widely recognized need for, and it would be highlyadvantageous to have, an approach which is effective in treating sleepdisordered breathing and yet is safe, minimally or non-invasive,reversible, and tolerable by patients.

SUMMARY OF THE INVENTION

According to one aspect of the present invention there is provided adevice for treating sleep disordered breathing comprising a device bodydesigned for positioning within a pharyngeal lumen and being designedand configured for: (a) maintaining an open airway during involuntaryclosure of the pharyngeal lumen; and (b) enabling sealing of the airwayduring swallowing.

According to further features in preferred embodiments of the inventiondescribed below, the involuntary closure of the pharyngeal lumen iscaused by collapse of airway tissue during sleep.

According to still further features in the described preferredembodiments the device body is configured as a tube.

According to still further features in the described preferredembodiments a lumen of the tube is maintained open during sleep.

According to still further features in the described preferredembodiments a lumen of the tube closes during swallowing.

According to still further features in the described preferredembodiments the device body is configured as a double wishbone.

According to still further features in the described preferredembodiments the tube is configured capable of being crushed by a forceof about 30 grams or less.

According to still further features in the described preferredembodiments the tube is selected having a length of 10-40 mm and adiameter of 3-12 mm.

According to still further features in the described preferredembodiments a lumen of the tube is selected having a diameter of 5-10mm.

According to still further features in the described preferredembodiments the device further comprises an anchoring element attachedto the device body, the anchoring element being anchorable to or withina nostril, a nasal cavity or nasopharyngeal tissue.

According to still further features in the described preferredembodiments the anchoring element is attached to the device body via atether.

According to still further features in the described preferredembodiments the tether is selected having a length of 0.5-10 cm.

According to still further features in the described preferredembodiments the tether is an elastic tether.

According to still further features in the described preferredembodiments the tube is made from a material with a coefficient offriction of 0.2 or less.

According to still further features in the described preferredembodiments a lumen of the tube is coated by or fabricated from ahydrophobic substance.

According to still further features in the described preferredembodiments the device body, anchoring element and tether are selectedsuch that when the anchoring element is anchored to or within a nostril,nasal cavity or a nasopharyngeal tissue, the device body resides withina nasopharyngeal or oropharyngeal lumen.

According to still further features in the described preferredembodiments the device further comprises at least one sinker elementattached to the device body, the at least one sinker element beingcapable of extending down below a base of a tongue when the device bodyis positioned within a nasopharyngeal or oropharyngeal lumen.

According to still further features in the described preferredembodiments a distal end of the at least one sinker element is capableof extending into the gastrointestinal tract.

According to another aspect of the present invention there is provided adevice for treating sleep disordered breathing comprising a device bodydesigned and configured for minimizing resistance to airflow throughcollapsed airway tissue while enabling sealing of the airway tissueduring swallowing.

According to still further features in the described preferredembodiments the device body is configured as a sheet or thin tube coatedwith or fabricated from a hydrophobic material.

According to still further features in the described preferredembodiments the device further comprises an anchoring element attachedto the device body, the anchoring element being anchorable to or withina nostril, nasal cavity, or nasopharyngeal tissue.

According to still further features in the described preferredembodiments the anchoring element is attached to the device body via atether.

According to still further features in the described preferredembodiments the hydrophobic material is PTFE.

According to still further features in the described preferredembodiments the hydrophobic surface functions in minimizing resistanceto air flow.

According to still further features in the described preferredembodiments the device body is coated by or made from a material with acoefficient of friction of 0.2 or less.

According to yet another aspect of the present invention there isprovided method of treating sleep disordered breathing comprising (a)positioning a device within a pharyngeal lumen, the device beingdesigned and configured for: (i) maintaining an airway or minimizingresistance to airflow during sleep; and (ii) enabling sealing of theairway during swallowing.

According to yet another aspect of the present invention there isprovided system for treating sleep disordered breathing comprising thedevice of the present invention and an applicator designed andconfigured for delivering and positioning the device within a pharyngeallumen through the nose or mouth.

The present invention successfully addresses the shortcomings of thepresently known configurations by providing a device capable ofmaintaining an open airway in collapsed airway tissue or minimizingresistance to airflow therein, especially during sleep and periods ofloss of muscle tone.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although methods and materialssimilar or equivalent to those described herein can be used in thepractice or testing of the present invention, suitable methods andmaterials are described below. In case of conflict, the patentspecification, including definitions, will control. In addition, thematerials, methods, and examples are illustrative only and not intendedto be limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication withcolor drawing(s) will be provided by the Office upon request and paymentof the necessary fee.

The invention is herein described, by way of example only, withreference to the accompanying drawings. With specific reference now tothe drawings in detail, it is stressed that the particulars shown are byway of example and for purposes of illustrative discussion of thepreferred embodiments of the present invention only, and are presentedin the cause of providing what is believed to be the most useful andreadily understood description of the principles and conceptual aspectsof the invention. In this regard, no attempt is made to show structuraldetails of the invention in more detail than is necessary for afundamental understanding of the invention, the description taken withthe drawings making apparent to those skilled in the art how the severalforms of the invention may be embodied in practice.

In the drawings:

FIGS. 1A-B illustrate an MRI image of a transverse cross section at thelevel of the oropharynx showing an airway opening (black opening witharrow) in a collapsed state (FIG. 1A) and in an open state (FIG. 1B).

FIGS. 2A-B illustrate the relevant anatomy labeled in sagittal andposterior cut-away views.

FIGS. 3A-B illustrate positioning of a tube embodiment of the presentdevice.

FIGS. 4A-B illustrate positioning of a wishbone embodiment of the deviceof the present device.

FIGS. 5A-B illustrate positioning of a sheet embodiment of the device ofthe present device.

FIG. 6 illustrates the device described in Examples 1 and 2 overlaid ona sagittal view of the relevant anatomy and

FIG. 7 is an endoscopic image showing a view down through the presentdevice and into the airway of a subject.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to a novel approach for treating sleepdisordered breathing. Specifically, the present invention relates todevices and methods for minimizing resistance to airflow, or maintainingan open airway, through collapsed airway tissue while maintaining normalpharyngeal functions and being safe, reversible and highly tolerable forthe patient.

The principles and operation of the present invention may be betterunderstood with reference to the drawings and accompanying descriptions.

Before explaining at least one embodiment of the invention in detail, itis to be understood that the invention is not limited in its applicationto the details set forth in the following description or exemplified bythe Example. The invention is capable of other embodiments or of beingpracticed or carried out in various ways. Also, it is to be understoodthat the phraseology and terminology employed herein is for the purposeof description and should not be regarded as limiting.

Although numerous approaches for treating sleep disordered breathing arepresently available, none are as effective as the continuous positiveairway pressure (CPAP) approach which remains the gold standard oftreatment.

However, due to low patient acceptability and compliance, alternativesto CPAP are constantly sought after.

Effective treatment is hindered by several factors. Although the softpalate, tongue and pharyngeal walls have all been implicated aspotential targets for treatment, the involvement of these tissues in theetiology of the disorder varies from one individual to the next. Inaddition, since these tissues are also involved in activities such asswallowing and talking, modification thereof can lead to discomfort orreduced function during waking hours. Furthermore, the airway tissuesare extremely sensitive to touch and mechanical forces in general. Asthese tissues are quite dynamic, any object coming into contact withthem can cause significant discomfort unless properly designed andconfigured.

While reducing the present invention to practice, the present inventorsrealized that successful treatment of sleep disordered breathing can beachieved by maintaining a minimal airway opening or by minimizingresistance to airflow at the region of airway closure without directlymanipulating airway tissue.

During sleep disordered breathing, pharyngeal and palatal tissuescollapse to substantially reduce the patency of the airway at the lowernasopharyngeal and oropharyngeal regions. In individuals suffering fromsleep disordered breathing such collapse can lead to complete closure ofthe airway and cessation of breathing.

Studies have shown that airway muscle tissue loses tone intermittentlywhen a person sleeps and that this loss of tone leads to collapse ofthis tissue and obstruction of the airway. As is illustrated in FIGS. 1a-b, collapse of pharyngeal tissues (including the lateral and posteriorpharyngeal walls, the soft palate and the tongue) transforms thesubstantially round or oval airway opening into a narrow slit-likestructure which is susceptible to further collapse and complete closureunder the vacuum formed by a lung trying to expand. The narrow lumenforms a Bernoulli or venture tube, which further reduces the airpressure at the constriction and strengthens the seal. Furthermore,since airway tissue is covered with sticky mucus secretions, the sealbetween the hydrophilic tissues becomes airtight and is only relievedwhen the person awakens due to lack of oxygen, thereby restoring tone toairway tissues and as a result opening the airway.

FIG. 2 a illustrates the relevant anatomy in a sagittal section whileFIG. 2 b illustrates the same anatomy in a posterior cut-away view wherethe posterior pharyngeal wall has been sliced open along its midline andthe pharynx and esophagus opened to expose the relevant tissues lookingfrom the back of the head towards the front (relevant tissues arelabeled).

Experiments have shown that nasal airway tubes having an internaldiameter as small as 3 mm (J S Nahmias et al., Chest 1988; 94;1142-1147) can help bypass the blockage formed by airway tissue collapseduring sleep and restore ordered breathing, however such tubes are meantto be rigid enough to self introduce every night, and thereforeuncomfortable and not designed for long-term placement in the airway.From this experiment one learns that a device which can maintain anopening through the collapsed airway sufficient for supporting orderedbreathing would be capable of treating sleep disordered breathing in asubject suffering from, for example, sleep apnea. However theseexperiments have also shown that traditional nasal airway tubes whichare made rigid enough for direct intubation are highly intolerable andas such were not used long term by most of the patients in the study andare therefore not practical solutions to sleep disordered breathing.

As used herein, the phrase “airway tissue” refers to tissue which formsor surrounds the airway. Such tissue includes the tongue, the soft andhard palate, the uvula, the pharyngeal walls, pharyngeal mucosa, floorof the nasal cavity, nasal septum, nostrils, turbinates, tonsils,adenoids and related lymphoid tissues, epiglotis and any surroundingtissues including, the tonsillar pillars, the levator and tensorpalatini muscles, and numerous other muscles (hyoglossus, styloglossus,stylohyoid, stylopharyngeus, palatoglossus, palatopharyngeus andpharyngeal constrictors) that have varying functions.

Thus, according to one aspect of the present invention there is provideda device for treating sleep disordered breathing in a subject, such as ahuman subject.

FIGS. 3 a-b illustrate one preferred configuration of the present devicewhich is referred to herein as device 10. Device 10 includes a devicebody 12 and tether 14 which is attached to device body 12 and anchoringelement 16 (also referred to herein as anchor 16). Device body 12 andtether 14 are configured such that when anchor 16 is anchored to tissue,part of device body 12 remains in proximity to the uvula and as suchprovides an airway opening through the collapsed tissue.

Preferably, anchor 16 is anchored or attached to tissue in thenasopharynx, nasal cavity or nostril of the subject (specific anchoringschemes are described hereunder). In such cases, several approaches canbe used to maintain device body 12 in the correct position. For example,a tether 14 constructed from a rigid (yet somewhat elastic) material canbe configured to maintain device body in position and yet avoid contactwith surrounding tissues. This can be achieved by curving a rigidportion of tether 14 (away from any tissue) and providing an elasticsoft portion at the region of the soft palate; since the soft palate isdynamic, a rigid tether 14 impinging on a moving soft palate can resultin discomfort to the subject.

Alternatively, tether 14 can be completely elastic and fabricated from,for example, a thin silicone tube. Due to the elasticity of tether 14,device body 12 of such a configuration can be displaced by forces suchas the upward forces applied by the soft palate during a swallow as itseals the nasal cavity or the force of air upwards through the nasalcavity during a cough or sneeze. To ensure proper positioning under suchforces, device 10 further includes one or more sinker elements 18 whichact to maintain device body 14 in the desired position in the pharynx.Sinker elements 18 are attached to device body 12 opposite the point ofattachment of tether 14 and act to counterbalance forces applied todevice body 12 by upward movement of the soft palate for example. In anelastic tether configuration of device 10, movement of the soft palateduring swallowing and talking would displace device body 12 up into thenasopharynx and therefore out of its functional position. Use of sinkerelements 18 or another form of biasing element ensures that such forcesare countered or dampened. Sinker elements 18 can extend down and hookaround the forward edge of the arch of the soft palate or extend behindthe base of the tongue (into the laryngopharynx), the epiglottis, theesophagus or into the stomach or even deeper into the GI tract. In thecase of sinker elements 18 that extend into the GI tract, the distalends (ends within the GI tract) of sinker elements 18 can be configuredwith an element for facilitating capture of sinker elements 18 by theperistaltic waves of the esophagus, stomach or duodenum in order to pulldevice body 12 into position. Such an element can be a ball orthickening in sinker elements 18 (for example a tassel-like distal end)which can be fabricated from a biodegradable/bioerodable material whichdisappears over time leaving only the lines themselves to provide agentle traction force on device body 12.

Additionally, the resulting vector from the tension of tether 14, devicebody 12 and sinker element 18 creates a downward and forward force onthe soft palate, also acting to open the airway and prevent the rearwardcollapse of the soft palate against the posterior pharyngeal walls.

Indeed, the entire device 10 or portions thereof can be biocompatibleand dissolvable over time (for example made of a hydrogel) to degradeand disappear following their intended service time. Since the in vivodegradation time of such materials is well known in the art, design ofdevice 10 or portions thereof capable of such timed degradation is wellwithin the capabilities of the ordinary skilled artisan.

A device positioned between the soft palate and posterior pharyngealwall provides several advantages when used in conjunction with sleepdisordered breathing. Such a device is always positioned in the regionof collapse thus ensuring that a patent airway is always maintainedduring sleep. In addition, the device is capable of maintaining an openairway under sleep-induced collapse (maintaining an outwards pressure onthe tissue which is equivalent to approximately 10 cm of water) and yetcollapses under greater tissue pressure (during swallowing and talkingfor example) thereby ensuring that velopharyngeal sealing functions aremaintained. Finally, the device can have a non-stick or low coefficientof friction surface thereby ensuring that mucus secretions do notaccumulate within the device and that peristaltic forces on device body12 are minimized due to its low friction within the pharyngeal lumen. Inaddition, the fact that the tube shaped device collapses underswallowing pressures also ensures further cleaning by collapse-mediatedpurging of any material trapped within the tube. Device 10 can include aplurality of device bodies 12 working independently in parallel or inseries or in combination to provide a patent airway during sleep.

According to one embodiment of the present invention, device body 12 isstructured as a round or oval tube with an internal diameter of 2-10 mm,a wall thickness of 0.01-1.0 mm and a length of 1-4 cm. The device ispositioned between the uvula and the posterior pharyngeal wall. Giventhat an open airway can be an oval with approximately 2-3 sq cm in crosssectional area during normal breathing, the device with a crosssectional area of 0.03-0.75 cm² is small enough to only tangentiallytouch an airway tissue and not interfere or apply forces on other partsof the airway during normal breathing. Such a device can be fabricatedfrom silicone of various hardness (for example Shore A 0-100) or fromanother biologically compatible polymer such as for examplepolyurethane, latex or poly-tetrafluoroethylene (PTFE), metal such astitanium or alloys such as Nitinol (bare or covered with a polymer). Inany case, the device is designed such that it resists a crush force of5-50 grams, or preferably 10-25 grams per 2 cm length thereby beingcapable of supporting the pharyngeal walls against collapse during sleepand yet at least some portion of the tube flattens (crushes) and sealswhen greater pressure is applied thereto, by for example, pharyngealwall pressure applied during swallowing, eating, speaking, coughing etc.The numbers above are derived from the universal efficacy of 10 cm ofH₂O as delivered by modern CPAP machines which form an “air splint” thatopens collapsed airways, mainly in the lateral direction, but also inthe anterior posterior direction. Device body 12 is configured toprovide similar uniform pressures on the collapsing airway tissues. Forexample, a 2 cm long by 6 mm diameter tube with a wall thickness of 0.35mm made of silicone of shore A 60 can resist a crush force ofapproximately 30 grams. Another combination giving similar stiffness isa tube 2 cm long, 8 mm diameter with a wall thickness of 0.6 mm made outof shore A 5 as described later in Example 1. Such tubes aresufficiently stiff to provide a patent airway yet soft enough to notirritate sensitive airway tissue, and collapsible enough to form a sealthat provides velopharyngeal sufficiency during swallowing, talking andcoughing. Finding the right balance between proper stiffness andcollapsibility is key to the functioning and tolerability of the presentdevice.

Thus, any tube which can maintain such forces on the tissue at theregion of collapse would be suitable for use with the present invention,provided such a tube would collapse under greater forces, such as thosepresent during swallowing, eating or speech. As is further describedhereinunder, the tube device utilized by the present device can be ofuniversal fit, or custom fitted to each individual by measuring thetissue closure force at the region of interest using a manometer whichcan be temporarily introduced through the nostrils or oral cavity on acatheter or a handle. Device body 12 would then be constructed to becrushable/collapsible under such forces, but yet stiff enough to act asa “return spring” to outwardly displace airway tissues that have losttone during certain stages of sleep.

In yet a further embodiment, device body 12 can include biasing elementsthat function to fix or bias its radial position in the lumen. Forexample, device body 12 can be centered using symmetrical elasticbiasing elements extending radially from device body 12 or as a tubewithin a tube structure. Alternatively, device body 12 can be biasedagainst one side of the lumen using an asymmetrical biasing element. Anadvantage of biasing device body 12 to the side is that it can be placedlower down the arch of the tonsillar pillar region without being grabbedand swallowed by the base of the tongue in the central higher portion ofthis “window” behind the uvula.

Device body 12 or portions thereof of this embodiment of the presentinvention can have a cross sectional shape of a circle, oval, D oreye-shaped and is positioned within an airway of the subject.

An additional configuration of device body 12 is substantially an opentube having a C-shaped cross section when uncompressed. Under thepressure exerted thereupon by pharyngeal and palatal tissues duringsleep (induced by collapse of such tissues), the C-shaped device body 12forms a closed tube which extends through the collapsed tissues therebyproviding a path therethrough for air to flow from the nasal cavity intothe trachea. Under greater forces, such as those present duringswallowing and talking, the C-shaped tube flattens into a sheet (or thetissues fold in around the C shape) enabling sealing between the palateand posterior pharyngeal wall, thereby ensuring that normalvelopharyngeal function is maintained. Alternative cross sectional areashapes of device body 12 are a tube-forming spiral, a sharp or wavy V,W, I-beam, star, or yin-yang shape. An additional configuration fordevice body 12 is a round or oval O-ring (or multiple O-rings arrangedin a bird cage fashion) that is suspended in the pharynx behind the softpalate. The top portion of the 0 ring is used to tether or anchor it.The side portions apply sideways force to the lateral pharyngeal walls.The bottom portion of the O ring can serve as the sinker element behindthe base of the tongue to keep the device positioned properly.

Device body 12 or portions thereof may be made of hydrophobic materialand as such even a very thin flat or ridged sheet of hydrophobicmaterial and/or material with a sufficiently low coefficient of frictionmay sufficiently reduce the sealing ability of the collapsed airwaytissue, and therefore make it easier to restore airflow. In other words,it is easier to move air in between a hydrophobic surface and a tissuesurface or between two hydrophobic surfaces than between two hydrophilictissue surfaces of a moist airway that has collapsed. In essence, ahydrophobic device body 12 acts as a permanent “surfactant” or“non-stick surface” (non-wetting surface) in the pharynx and lowers thesurface energy required to peel apart the collapsed portion of an airwayand move air through it.

As used herein, “hydrophobicity” implies contact angle of water of >90degrees, while superhydrophobicity implies contact angle of waterof >150 degrees.

The surface energy property of the material used can be a function ofthe underlying material, its geometry or a combination of both. Forexample, polyester fibers coated with tiny silicone filaments form asuperhydrophobic yet highly flexible surface (see Zimmermann et. al.,Advanced Functional Materials V18, 22, 3662-3669, 2008). Various surfacetreatments, such as gas deposition or laser or plasma etching can beused to modify the free surface energy or contact angle of anyparticular material as is well known in the art.

Hydrophobic materials/coatings are advantageous in that they allow airto pass through the collapsed airway easily, do not allow water insidedevice body 12 to collapse the tube, do not clog with secretions sincesecretions will not adhere to inner walls and act to prevent device body12 from being fouled with biofilms.

Suitable materials include PTFE (e.g. Teflon™) which has a contact angleof around 110 degrees and bare silicone which has a contact angle of˜90-110 degrees. Device body 12 can be configured as a thin sheet rolledinto a tight cylinder or “crumpled” by the collapsing airway. Such aconfiguration maintains enough of a passageway when collapsed orcrumpled through small channels which enable air passage through thecollapsing airway. Such small airways can “prime the flow” of largervolumes of air through a collapsed airway.

Alternatively, device body 12 can be one or more strips, sheets or atube made of thin (0.5 to 50 mil thick) PTFE that is hydrophobic on bothsides or made hydrophilic on the back surface (by etching or addition ofa hydrogel for example). Such a device body 12 would adhere to theposterior and lateral pharyngeal walls. Preferably, the front surface ofdevice body 12 is very hydrophobic (contact angle of water >90 degrees)and as such it provides a low friction surface for the uvula and tonguebase thereby minimizing sensation and peristaltic forces trying toswallow device body 12. For example PTFE has a coefficient of frictionof around 0.1, which minimizes the forces trying to swallow device body12 in the oropharynx. Parts of device body 12 (or optionally sinkerelement 18) with higher coefficients of friction can extend down belowthe tongue base and be pulled down constantly against the tension oftether 14 and anchor 16 in the nasal cavity as per FIGS. 5 a-b. Duringairway collapse, the hydrophobic surface of the PTFE sheet restingagainst the soft palate and tongue base would be easily peeled by airand allow the airway to open. Semi-rigid topographical features on thissurface, such as little channels or ridges can also prevent a tight sealand help air pass through.

In yet another embodiment, the sheet has one or more central bumps,channels, gutters or parallel waves or ridges in the center or sides ofotherwise flat device body 12. These bumps and protrusions can be adeformation of the same material from which device body 12 is made andcan easily be formed by vacuum forming or molding technologies. Thesebumps, grooves ridges, channels, waves, and/or protrusions, collectivelytermed “topographical features” can protrude smoothly from thesurrounding material and as a result would not cause any significantsensation when the pharyngeal walls, soft palate, uvula, tongue base orepiglottis rubs up against these structures. Optionally, thesetopographical features can be pressed flat during the forces present inthe oropharynx during a swallow or while talking. Yet during loss ofmuscle tone, these topographical features allow for a minimal airchannel (that can then expand into a full air channel) or gently forcethe soft palate and base of the tongue forward and/or lateral pharyngealwalls sideways, thereby allowing air to flow within or adjacent to thesetopographical features. In this configuration, device body 12 or aportion thereof can extend lower than the uvula so that a peristalticforce of the tongue and esophagus plays a role in keeping the sheetflat, taught and well positioned in the pharynx.

With respect to device 10 residing in the lumen of the airway, theminimal thickness of the sheet-shaped device body 12 enables it to bevery tolerable. If device body 12 gets crumpled up during airwaycollapse, device body 12 folds on itself such that hydrophobic surfacesface other hydrophobic surfaces, thus minimizing resistance to air flow.Device body 12 in this embodiment can be made of any flexiblehydrophobic or super-hydrophobic material, such as for examplepolyurethane, silicone and/or PTFE, or combinations of such polymersgiving optimal softness, structural integrity and hydrophobicity. Thesheet forming device body 12 can have very soft or rounded edges, such asilicone bumpers, to minimize discomfort of the edges as they contactsensitive airway tissue. The coefficient of friction of the materials orcoatings used for device body 12 or portions thereof may be less than0.5, preferably less than 0.25 and more preferably less than 0.15.

FIGS. 5 a-b illustrate an embodiment of device body 12 which isconstructed from an oval-shaped thin sheet of material with at least onehydrophobic surface and an oval-shaped central bump as the topographicalfeature that keeps gentle forward pressure on the uvula and soft palate.Device body 12 of this embodiment is depicted as being anchored to theposterior pharyngeal wall with anchor 16 that can take the form of anyof the anchoring schemes described herein or known in the art. Devicebody 12 also is depicted as minimally extending into the oropharynxwhere the peristaltic forces of the tongue and other tissue helps keepit in position. It is also possible to combine device body 12 in thisembodiment with the concepts of tether 14 and sinker elements 18.

In an alternative embodiment, device body 12 can be a thin (e.g.0.001-0.5 mm wall thickness) polymeric tube with a cross sectional areaof up to the open airway (e.g. ˜1 to 4 sq cm) tethered via tether 14 toanchor 16 in the nasal cavity. Alternatively device body 12 can includea larger diameter semi-rigid ring along its top edge (proximal edge)that acts as anchor 16 to prevent downward migration of device body 12in the pharynx, much like a contraceptive diaphragm or pessary is heldin position in the vagina. In this embodiment, the structural stiffnessof device body 12 is negligible in the fully open positions, but uponconstriction of the pharyngeal opening the hydrophobic inner surfaces ofdevice body 12 will not seal as tightly as collapsed airway tissue, andtherefore air will pass through the airway through this “non-stick”lining. The outer layer of device body 12 in this configuration can behydrophilic to attach itself to the airway tissues and act to keep thetube open. Alternatively, the tube can be made of a material (forexample a thin PTFE extruded tube) that has sufficient rigidity to stayopen while still being crushable elastically. Furthermore, the crumplingof device body 12 from its open diameter of around 5 to 25 mm to itsfully constricted state during airway collapse will form wrinkles andridges which will enable air to escape through the region of collapse.Mucous and other secretions will flow both around and within device body12, whose opening is wide enough to not be clogged. Device body 12, ifsized to take up most of the cross sectional area of an open airway (1-4sq cm cross sectional area) will not move much within the airway andtherefore not cause any major sensation. Furthermore, device body 12 canhave a cutaway portion that does not extend behind the base of thetongue or the epiglottis to prevent the device from being swallowed.Alternatively, a region of device body 12 (for example the back surface)or sinker elements 18 can be exposed to the peristalsis of the tongue oresophagus to keep device body 12 properly positioned against therestraint of tether 14. The surface tension effect might be sufficientso that the mechanical stiffness of device body 12 can be negligible(e.g. as low as 1 mil or 0.02 mm thick silicone, polyurethane,polyetheretherketone (PEEK) and/or PTFE). In this fashion, device body12 is not a stent in the traditional meaning of the word as device body12 does not even need to touch the airway tissue under restingconditions, nor can device body 12 supply any significant radial forceson the tissue against which it is resting. Rather it acts as acollapsible “non-stick” surface or lining in the lumen of the airway.

Furthermore, the surface tension effects described above and mechanicaleffects of device body 12 that supply radial forces to prevent the totalcollapse of the airway can be utilized synergistically.

Device body 12 or portions thereof can be pleated, accordion-like, orhave sections of varying cross sectional stiffness to accommodatechanging axial and radial curvature of the anatomy or to providepreferential sites of elastic crushing (e.g. different shore hardness,different thickness walls, thin wall thicknesses stiffened withinterspaced ribs or hoops, etc). Device body 12 or portions thereof canhave flared ends (either in or out), slanted, flapped, thinned orrounded ends or ends of lower shore hardness to minimize any undesiredmechanical stimulation of the airway tissue by the edges of device body12. Device body 12 or portions thereof can have varying shore hardnesslayers to achieve the same effect (e.g. shore A 60 on the inside formechanical stiffness and shore A 3 on the outside for a soft interfacewith the airway tissue).

Device body 12 can be collapsible to a flat profile during the day tominimize interference of the normal anatomy and assume a circular crosssection during sleep based on a manually-activated mechanism or based onthe automatic detection of apnea. For example, device body 12 can onlyopen or inflate when a flow sensor inside it senses that no air is goingthrough the device for a set period of time, at which point an actuatormechanically opens the tube or a mechanism inflates the device body intoa shape that forms an airway or simply pushes away collapsed airwaytissue to restore a patent airway. The device can contain on boardelectronics and actuators and be charged inductively through aconduction coil placed in the oral cavity for a few minutes a day, forexample. Alternatively, the device can connect to a power or compressedgas source through a minimal connection at night. In an alternativeembodiment, device body 12 can be inflated or stiffened through thetransfer of gas or fluid though a manually or automatically activatedpump mechanism (introduced into or present in the nasal cavity forexample).

To prevent clogging, the device can be coated with a low coefficient offriction and hydrophobic material (e.g. Teflon™) or super-hydrophobiccoatings (e.g. silicone fluorinated with fluoroalkylsilane),anti-fungal, anti-bacterial, anti-viral or other non-fouling coatings(such as Surfacine™), incorporate silver or other agents to keep thesurfaces bacteriostatic or bacteriocidal, or be constructed so as tominimize clogging, fouling or the adherence of a biofilm by ensuringthat the surface is extremely smooth (for example filler-free siliconescast in highly polished nickel-coated molds or extruded PTFE tubing).The occasional crushing of the tube closed against the airway tissueduring routine swallowing and talking would force out any secretions inthis short tube and therefore clean it. The device can also haveopenings in the tube along its length, ranging from 1% to 99% of thetotal open/closed surface area ratio. Such openings are designed foradding flexibility to the tube and minimizing clogging by enablingevacuation of any secretions, yet a device provided with such openingstill maintains a general tube shape within collapsed tissues and thusmaintains an open airway. Furthermore, if device 10 inadvertentlydetaches from its anchor site or if device body 12 detaches from tether14, there is the possibility of device 10 or portions thereof beingaspirated or swallowed. To increase safety, all portions of detacheddevice 10 can be made small enough not to fully obstruct an airway ifaspirated, and can travel harmlessly through the GI tract and be removedfrom the body via defecation if swallowed. This feature is anotheradvantage of utilizing the small and collapsible device body 12 of thepresent invention.

In a further embodiment, device body 12 or portions thereof can act as areservoir of active agents (e.g. drugs), that can be eluted into thepharynx over time in a controlled manner. The active agent in devicebody 12 can be replenished from outside the body using a hollow tubeforming tether 14. In this configuration, device 10 can function as adrug delivery system for indications such as sinusitis, sore throat,strep throat, tonsillectomy, throat surgery, viral and bacterialinfections, and as a nasal drug delivery system in general. Examplesagents that can be eluted, passively or actively released from devicebody 12 include antibiotics, antiviral drugs, local anesthetics,analgesics, peptides, hormones, small molecules and the like for eitherlocal or systemic delivery through the pharynx's mucosal surface. In oneembodiment, device body 12 is an elastically inflatable reservoirpresent in the nasal cavity above the hard palate with tether 14 being afill tube with a one-way check valve or septum interface and the activeagent being dispensed through one or more orifices in device body 12.Control of the delivery of the active agent can be through active means(actuator) or passive means (pressurized flow through an orifice).

In one embodiment, device body 12 is connected to anchor 16 via tether14. In an alternative embodiment, device body 12 can be connecteddirectly to anchor 16 without tether device 14.

The present device can be anchored to any airway tissue using any of thefollowing elements or combinations thereof: elastic or inelastictethers, t-bar anchors, sutures, button-type anchors, hooks, magneticclasps, cages, clips and the like. For example, anchoring elements canbe delivered through the palatal tissue (at center by the uvula regionor on the side by the tonsillar pillar) and anchored thereagainst usingT-bar or button type stops preferably fabricated from a polymer such assilicone or a harder material coated with a polymer such as silicone.Such stops can be tethered to device body 12 using a polymer or they canbe fabricated as an integral part of the device.

Anchor 16 can be attached to device body 12 directly or to an applicator(further described below), which can position anchor 16 in theappropriate place or be used to drive anchor 16 through the tissue.

The functionality of the present device can also be achieved by usingdifferent configurations of device body 12. For example, a deviceconfigured with stiffeners extending through the region of collapse canbe used to maintain patency through collapsed tissue. Such a device canbe configured as, for example, device body 12 which consists of a doublewishbone which is fabricated, for example, from silicone coated Nitinolwire or a polymer such as polypropylene. Such a double wishboneconfiguration can be anchored to tissues above the soft palate, e.g. thenasal septum, via an anchoring ring or the like, and be sized andconfigured such that the wishbone arms extend through the region ofcollapse.

A straight piece of 0.01-0.02″ diameter Nitinol wire (bent in a 4 cmlong wishbone configuration) would supply enough force to maintainopening pressure on collapsed tissues (in the double wishboneconfiguration) and yet would bend under greater pressure (collapsingsuch that the distal ends of the wishbone touched or became very closeto one another) thereby allowing closure of the palatal and pharyngealtissues. Such a device can either be fully implanted as a stiffeningarch or reside in the airway itself and apply pressure to the airwaytissue.

An example of a wishbone-like device which is referred to herein asdevice 10 is illustrated in FIG. 4 a-b. In this embodiment device 10 hasdevice body 12 consisting of wish-bone arms running from the septum downalong the sides of the soft palate to a region close to the tonsillarpillars. Such a configuration applies gentle outward pressure on thelateral pharyngeal walls. The surface area of the distal arms of thewishbone device body 12 can be widened (e.g. form a loop or paddle) tomaximize the surface area pressing against the airway tissues. The armsof the wishbone can go straight up the sides of the soft palate in theform of an inverted square U shape and not interfere with the raisingand lowering of the center portion of the soft palate and uvula thatoccurs during swallowing and talking for example. Furthermore the armsof wishbone device body 12 can extend below the level of the uvula andstill not be exposed to the back of the base of the tongue and theepiglottis since they are on the sides of the soft palate arch and notin the center of the “window” through which the base of the tonguecontacts the posterior pharyngeal wall (best seen in FIG. 4 b). Devicebody 12 can be attached via a short and semi-rigid tether 14 to thenasal septum with anchor 16 or use any other anchoring scheme describedherein.

The applicator device used to introduce the wishbone device body 12 cankeep the arms folded together using a retractable over-tube, or bykeeping them bent together with a snare or water-dissolvable film untilthey are in position and ready to be deployed. This minimizes the sizeof device 10 as it is being introduced into the nasal cavity.

In the case where device body 12 is bulky, it is important to avoidhaving large areas of device body 12 contact the base of the tongue orthe epiglottis, as that will inadvertently allow swallowing forces topull device body 12 down and be uncomfortable for the user. If sinkerelements 18 are used, they should be of minimal cross sectional area(e.g. thin strips or small diameter soft tubing) so as to not be felt bythe user.

In an alternative configuration, there are more than two arms in thewishbone, thereby forming more of a bird cage or bent bow-tie shape.This configuration enables force in more than one radial direction (forexample anterior-posterior in addition to lateral directions) and allowsthe distribution of forces on a great surface area.

Configurations anchored above the soft palate (e.g. to the nasal septum)can also utilize open or closed tube or tube-like configurations. Suchconfigurations are preferably anchored such that they drop down alongthe lateral walls and thus provide an airway at the lateral sides of thenatural airway opening. Alternative configurations of device body 12providing such functionality can also be shaped as wedges rather thantubes. Such configurations can wedge apart collapsed tissues. Forexample, a V, L or I-beam-shaped device body which can be designed towedge apart the corners of the collapsed airway (at the lateralpharyngeal walls) thereby providing an airway opening during tissuecollapse.

It should be noted that device 10 of the present invention can alsoinclude a combination of the device body configurations describedherein. For example, the upper portion of device body 12 can be a tubeand the lower portion a wishbone so that the tube extends only as low asthe uvula and the wishbones extend down the lateral pharyngeal wallsinto the oropharynx. The wishbone therefore also acts to center the tubeof device body 12 in the airway. In another example, device body can bea thin sheet with a short tube section in the middle.

Effectively any structure that resides in the lumen formed in the lowerportion of the nasopharynx behind the soft palate and optionally theoropharynx and prevents the collapse of airway tissue or reduces thesurface energy required to move airway through the collapsed airwaywhile not compromising the ability of the lumen to be sealed duringswallowing is envisioned as a device body 12.

Any of the above described configurations can be delivered andpositioned via the nose or the mouth. Such delivery can be effectedusing a dedicated applicator. For example, a 2 mm OD Tygon™ tube with aninternal nylon line can be used to snare the distal end of device body12 and/or sinker element 18. The delivery tube and loaded device 10 canbe delivered together into the nasal cavity through a nostril. Devicebody 12 is small and collapsible so that it can deform to easily fitthrough the nostril and conchae. Once properly positioned in the back ofthe nasopharynx, oropharynx, laryngopharynx or esophagus, the internalnylon line forming the snare is pulled thereby releasing the distal endof device body 12 or sinker element 18. Swallowing will further pull onsinker element 18 and properly position device body 12 against thetension of anchor 16 and/or tether 14. The applicator tube is thenremoved from the nostril. Proper positioning of the device can bemonitored through the nasal cavity with the use of a nasal endoscope orthrough the oral cavity using direct visualization or with the use of amirror. Depth markings or mechanical stops on the applicator can helpguide the user or physician to make the delivery at the appropriateposition.

Alternatively, a soft, elastic and flexible tether 14 can be coated witha water-soluble material, such as a hydrogel like carboxymethylcellulose (CMC) which is then dried to allow the physician or the userto push device 10 into the nostril without an applicator. The coatingwill dissolve in the moist environment of the nasal cavity and pharynxand tether 14 will return to being soft, elastic and flexible.

In a further embodiment, device 10 can be preassembled on an applicatorand together they can lubricated with a lubricating gel such as KY™and/or an anesthetic gel such as lidocaine and packaged.

Device 10 can also be designed to be introduced and removed by the useron a daily basis. The removed device is either discarded and a new oneused or cleaned or disinfected for repeated use. Some portion of device10 can dissolve or degrade after a set amount of time to encourage thereplacement of the device. This approach helps to ensure that nobacteria or fungus colonize the device in the long term as it isfrequently replaced.

The user can be tested using a manometer-equipped device which can betemporarily positioned at the region of interest and used to measure theforces needed to maintain patency during tissue collapse as well as theforces exerted during non-sleep functions such as eating, swallowing,coughing and talking. In addition, the test device can also be used tomeasure the length and diameter of the device body 12 needed, therebyenabling selection of an optimal device body 12 (from a kit whichincludes tethers of varying lengths, device bodies of varying sizes andcrush strength).

The applicator can include an applicator head mounted on an operatinghandle. The applicator head can include a device engaging element(s) andone or more tissue penetrating elements for facilitating anchoring ofthe device into oral or nasal tissues. The applicator head can beintroduced trans-nasally or trans-orally if mounted on a swivel jointwhich can assume a selected angle (0-180°) with respect to the operatinghandle of the applicator.

The anchor and the device can be separated into two components so that alow profile empty anchor can be installed, and then tethers or devicebodies (e.g. tubes or wishbones) of varying lengths, size, geometry orstiffness can be positioned on the anchor. For example, device body 12with sinker element 18 can be introduced through the nostril of apatient by a doctor and partially swallowed by the patient,intentionally placing device body 12 too deeply in the pharynx. Tether14, whose proximal end remains outside the patient's nose, is pulled bythe doctor until an alignment mark on device body 12 is visible throughthe open mouth of the patient. Cage anchor 16 (described below) isinstalled in the nostril of the patient by the doctor and tether 14 isclipped to cage anchor 16 and excess tether 14 is cut off to finish theprocedure. The device and the anchor can be connected via a permanent orreversible element, such as a latch, suture or magnetic clasp. Aconically-shaped, cylindrically-shaped, or two rings or C-shaped ribsconnected by one or more short spines made of a biocompatible metaland/or polymer can also be constructed to fit elastically as a cageanchor 16 within a nostril while preventing migration further into thenasal cavity (see FIGS. 3 a-b for an example cage anchor inside thenostril of a subject). Tether 14 can be attached to this cage anchor 16.The profile of this cage can be minimized so that it is not externallyvisible, does not obstruct airflow, can pass through a GI tract ifinadvertently swallowed, and can be comfortable worn for many months.Grabbing the cage either directly or with a tab, pull string ordedicated removal tool allows complete removal of device 10 in a matterof seconds.

Alternatively, tissue penetrating elements can serve to penetrate thetarget tissue and deliver anchor 16 (which can be attached to devicebody 12 or tether 14) into the tissue thereby anchoring the device atthe correct position. In one embodiment, anchoring is facilitated by aset of one or more needles which are pre-spaced and are introducedthrough the oral cavity from behind the soft palate or trans-nasallythrough the nostril. The needles are connected to the anchoring element,which can be a T-bar, barb, button, ball and the like.

Preferable locations to anchor include the fibrous cartilage at front ofseptum, the mucosal covered cartilage deeper in the septum, the vomer orperpendicular wall of the ethmoid bone in the back of the nasopharynx.

When anchored to soft tissue, device body 12 can be made out of asilicone tube out of which emerge two short silicone tethers withsilicone buttons that are in turn overmolded onto a suture thread withis attached to a suture needle. The suture needle is pushed through thesoft palate from behind. The suture pulls the buttons through the tissueto the anterior surface of the soft palate. The suture thread is cut andthe device is then anchored to the back side of the soft palate with twosilicone tethers that go through the tissue and terminate in twosilicone buttons on the front side of the soft palate for a fullyflexible and elastic tethering system that is capable of conforming tothe dynamic anatomy of the soft palate. It is expected that the tunnelthrough the soft palate will re-epithelialize and therefore not be atract for infection, much like a tract formed in the tongue when it ispierced by a tongue stud. Furthermore, the buttons can be cleaved forquick removal of the device for a fully reversible procedure.

The applicator can consist of a vacuum cup to suck in a known volume anddepth of tissue and then penetrate this tissue with a needle, releasingan anchor 16 (such as a T bar) on the other side of the sucked-in tissuepocket or fold. The anchoring element running through the tissue pocketor fold can be traditional suture thread (such as polypropylene) or anelastic tether (such as silicone).

The tissue penetrating elements can include a needle, a slotted needleor a lancet. The tissue penetrating elements can move in and out of theapplicator head and be actuated via a trigger release mechanism. Such arelease mechanism can be triggered to forcibly push the tissuepenetrating elements out of the applicator head and into the targettissue. The tissue penetrating element can also be configured to eluteor deliver a local anesthetic such as lidocaine to provide for painlessanchoring.

The applicator can further include a device release mechanism (e.g.plunger) for releasing the device once it is in the desired positionwithin the tissue. Delivery and positing of the present device ispreferably effected under local anesthesia, while airway tissue is undertone, and thus does not require the physician to manipulate tissueanatomy prior to administration of the device.

It may be advantageous to perform the procedure under local anesthesiaand to temporarily reduce normal muscle tone on purpose, by inducingmuscular paralysis by Vecuronium, or sedation using propafol forexample, and thereby to allow the physician to determine the optimaldevice position based on the anatomy of the collapsed airway. Suchtemporary paralysis may also inhibit the gag reflex which will allow thephysician better access to the airway tissues when performing theprocedure without causing the patient to gag if done through the oralroute. If delivery is done through the nostril in a trans-nasal route,there is usually no gag reflex. Collapsibility of the tissue can bedetermined in real time using the Mueller maneuver or by over or underpressurizing the airway in a controlled manner, and any suchcollapse-prone regions identified as a candidate implantation site.

Procedures performed under general anesthesia may require manipulationof tissue in order to mimic the anatomy present when the airway tissueshave baseline muscle tone since general anesthesia relaxes muscle tissueand could lead to collapse of airway tissue.

Delivery of the present device can be monitored via direct visualizationor via an endoscope positioned through the mouth or nose, this isparticularly important in delivery through the oral cavity into the softpalate to avoid a situation where due to misalignment the implantprotrudes into the nasal cavity instead of residing in the tissue ofinterest.

The present invention also envisages oral/nasal appliances for providinga patent airway and for modifying the position and stiffness of the softpalate.

Thus, according to another aspect of the present invention there isprovided an airway appliance configured for modifying palatal tissue.

Three configurations of an airway appliance are envisaged herein. Afirst configuration includes a device body that resides behind the softpalate. In one embodiment, the device body is a short tube behind thesoft palate similar to the configuration in FIGS. 3 a-b. The device bodyis reversibly attached to the uvula or the arch of the soft palate onone end and a tether running up the nasopharynx on the other end.Tension on the tether keeps the tube snug on the back of the softpalate, even during its full range of motion. Tension can be applied tothe tether prior to sleep and maintained throughout the sleep period viaan automatic or manually effected shortening of the tether, through aclasp mounted on the septum near the nostril for example. Tension on thetether can be relieved during waking hours to enable natural speech andeating functions.

In an alternative embodiment, the top end of the tether can terminate ina ring or funnel or ribs that stays lodged in narrowing nasopharynxroughly at the height of the hard palate. In yet a further embodiment,the device body is anchored via a tether to external nostril using anose-clip or internal nostril cage. The advantage of the aboveconfigurations is the totally non-invasive aspect of the anchoring thatrequires no tissue penetration.

In an alternative embodiment, the device body is free to slide along thetether via a manual or automatic mechanism. During waking hours, thedevice body resides above the soft palate in the nasal cavity where itdoes not interfere with soft palate and pharyngeal functions and atnight or during an apnea event, it is lowered into position behind thesoft palate to open the airway.

In a further embodiment, device 10 can take the form of a nasal-palatalappliance. The appliance includes tether 14 which runs from a nostrilopening through the nasal airway, around the top of the soft palate andinto the oral cavity where it is anchored. Tension on tether 14 pullsthe soft palate forward and up and the lateral pharyngeal walls slightlysideways, thereby preventing collapse of this tissue during sleep.During waking hours the tension in tether 14 can be relieved to allownormal functionality of the soft palate. Tether 14 of the device canterminate in soft hooks that hook from behind around the front edge ofthe soft palate arch. Tether 14 or applicator can be rigid enough orbiased in a forward arch to enable such hooks to be steered intoposition or elastically engage as soon as they emerge from behind thesoft palate in a trans-nasal approach. Alternatively, tether 14 isanchored at an oral cavity anchor, such as a dental bridge or hardpalate screw, for anchoring two elastic tethers 14 at each side of thetop back side of the oral cavity. Tethers 14, which act as elasticslings, proceed around the tonsillar pillar area, back behind the softpalate and up through the pharynx and terminate in the nasal cavity atan anchoring point. The cross section of tether 14, or portions thereof,can be round, flat like a ribbon, or porous like a mesh to engage asmuch surface area as possible. The device, or portions thereof, can bemade out of fully or partially elastic materials such as silicone orpolyurethane. Tension on tether 14 is set to pull the soft palate up,forward and to the side, thereby restoring a patent airway. It ispossible due to the elastic nature of the sling to find the minimumtension that allows for a patent airway at night while at the same timenot interfering with the functioning of the airway anatomy during wakingactivities (coughing, swallowing, talking, etc). Alternatively, tether14 can be tensioned differentially while awake or during sleep using apatient activated mechanism. Examples of such a mechanism include afinger-operated slider or length adjustment device mounted in the oralcavity, or a clasp anchored near the nostrils in the nasal septum thatallows the user to grab the hidden end of tether 14 and pull it tightduring sleep, leaving some portion of tether 14 exposed outside thenostrils. The latch is released upon awakening, thereby loosening thetether 14 and hiding the end of tether 14 in the nostril.

Another configuration of the device of the present invention utilizes adental bridge for pushing up, pushing sideways or pulling forward any orall of the soft palate, uvula, tonsillar pillars and lateral pharyngealwall. Such an appliance can include a pair of rearward projections, forexample fabricated from Nitinol wire covered with silicone. Theseprojections can be configured for projecting rearward and behind theairway tissue of interest. Optionally, this appliance can have two modesof operation, a day mode, in which the projections are sequesteredwithin the appliance or otherwise disengaged from applying steady-statepressure on airway tissue, and a night mode in which the projectionsprovide the desired support for the airway tissue of interest.

In this configuration, the device includes one or more elements forbiasing the soft palate up and optionally forward. Such elements can beattached to a dental bridge which can be mounted on the molars of theuser. The bridge and/or elements can be adjustable so to enableadjustment of force on the soft palate and toggling between day mode (noforce on tissue) and night mode (biasing of tissue). Such toggling canbe effected using a hinge or slider mechanism activated by the usermanually or through a remote or by fabricating elements from bendablematerial (e.g. Nitinol). The device can also be fitted with an optionaldevice body 12 such as a tube or wishbone (similar to that described inFIGS. 3 a-b and 4 a-b), thus also providing the functionality describedin context with these embodiment of device 10. Device body 12 can betherefore supported behind the soft palate from below. In all theconfigurations above, the device can also be used on a temporary basisto measure forces, determine efficacy in reducing SDB, and assist in theproper selection of a more permanent implant, such as those described inFIGS. 3, 4 and 5.

It will be appreciated that although the present devices are describedin context of treatment of breathing disorders such as apnea, such adevice or a modification thereof can also be utilized to treat snoringsince it can be used to modify the stiffness or dynamics of the relevantairway tissue and thus dampen the vibration or cushion the impactthereof during sleep related breathing. For example, in treatingsnoring, the tube embodiment of the present device can be modified intoa sling or smaller profile bumper (solid or hollow) which reduces thevibration and hence the noise generated by the vibrating airway tissues.It is anticipated that any form of device 10 described herein is usefulin reducing snoring as one aspect of sleep disordered breathing, inaddition to its utility in treating obstructive sleep apnea.

As used herein the term “about” refers to ±10%.

It is expected that during the life of this patent many relevantbiocompatible materials will be developed and the scope of the materialsused in device 10 is intended to include all such new technologies apriori.

EXAMPLE 1 Visualization of a Tethered Airway Device in a Subject

The device illustrated in FIG. 6 (without sinker element 18) wasconstructed and delivered in accordance with the teachings of thepresent invention and positioned with a nasopharyngeal cavity of a maletest subject. Device body 12 was made from a tube 2 cm long, 8 mm indiameter and 0.6 mm thick molded from silicone of shore A 5 and adheredto tether 14. Device body 12 was observed using in-vitro bench testingto crush closed when a 30 gram weight was placed on it with the weightuniformly distributed along the length of device body 12. 30 grams ofcrush force on the tube of device body 12 corresponds to a pressure of20 cm of water, which is more than the universally effective CPAPpressure of 10 to 15 cm of water. Therefore device body 12 is stiffenough to prevent airway collapse.

Tether 14 was fabricated from a 1 mm OD silicone tube made from shore A60 silicone. Attachment of tether 14 to device body 12 was via WackerE41 silicone adhesive. Tether 14 was attached to anchor 16 (an externalnose clip fabricated from silicone).

Device 10 was positioned using a 2 mm OD Tygon™ tube applicator (notshown) with a snare formed on its distal portion by an internally placednylon line inside the Tygon tube. The snare attached both device body 12to the applicator tube. The applicator and attached device 10 wereintroduced through a nostril of a male volunteer. Device body 12 waseasily delivered though the nostril with no discomfort to the subject.Local anesthesia was not required. Anchor 16 (nose clip) was attached tothe bridge between the nostrils of the subject and the length of tether14 was adjusted using adjustment loop 20 so that device body 12 restedat the height of the uvula as verified using direct visualization ofdevice body 12 through an open oral cavity. The subject reported nodiscomfort while device 10 was in the proper position.

A pediatric nasal endoscope was introduced through the nostril and usedto visualize device body 12 in the nasopharynx from above. The nasalendoscope was positioned just inside the top opening of device body 12and the inner lumen of device body 12 was verified to be open asillustrated in FIG. 7. In FIG. 7, the inner lumen of device body 12,distal round bottom opening 22 of device body 12, uvula 24 viewedthrough transparent device body 12 and epiglottis 26 are all visible inthe endoscopic picture. When the subject swallowed or talked, the innerlumen of device body 12 was observed to be crushed closed between thesoft palate and the posterior pharyngeal wall, thereby confirmingvelopharyngeal sufficiency and crush force of great than 30 grams. Thesubject reported no discomfort during this procedure, even whileswallowing or talking. Therefore it was demonstrated that the presentdevice has sufficient force to maintain a patent airway during sleep andairway collapse yet still is crushable enough to maintain velopharyngealsufficiency during swallowing with high patient tolerability. The nasalendoscope and device 10 were removed to conclude the experiment.

EXAMPLE 2 Use of a Tethered Airway Device in a Patient

The device illustrated in FIG. 6 was constructed and delivered inaccordance with the teachings of the present invention and positionedwith a nasopharyngeal cavity of a male test subject suffering fromsnoring and sleep apnea. Device body 12 was made from a tube 2 cm long,8 mm in diameter and 0.6 mm thick molded from silicone of shore A 5 andadhered to tether 14. Tether 14 was fabricated from a 1 mm OD siliconetube made from shore A 60 silicone. Attachment of tether 14 to devicebody 12 was via a Wacker E41 silicone adhesive. At the distal end ofsinker element 18 which measured 50 cm in length, a 4 mm ball ofsilicone was formed using the silicone adhesive. The 4 mm ball providedan object against which peristaltic forces worked to cause sinkerelement 18 to be swallowed and present in the stomach of the subject,thereby aligning device body 12 in the pharynx. Tether 14 was attachedto anchor 16 (an external nose clip fabricated from silicone).

Device 10 was positioned using a 2 mm OD Tygon™ tube applicator (notshown) with a snare formed on its distal portion by an internally placednylon line inside the Tygon tube. The snare attached both device body 12and the distal end of sinker element 18 to the applicator tube. Theapplicator and attached device 10 were introduced through a nostril ofthe male patient. Device body 12 was easily delivered though the nostrilwith no discomfort to the subject. Local anesthesia was not required.When sinker element 18 was in the upper esophagus, the snare wasreleased and the applicator tube slowly removed. Sinker element 18 wasthen swallowed by the subject along with a few sips of water. Anchor 16(nose clip) was attached to the bridge between the nostrils of thesubject and the length of tether 14 was adjusted using adjustment loop20 so that device body 12 rested at the height of the uvula as verifiedusing direct visualization of device body 12 through an open oralcavity. The subject reported no discomfort while device 10 was in theproper position.

The subject spent the day with device 10 in position and indicated noproblems in eating, drinking, swallowing, breathing or talking. Thesubject then slept with device 10 installed. A video and audio recordingof the night's sleep indicated that the subject did not snore nor did heenter into any apnea events. The subject spent most of the night on hisback, which is a challenging position as most snoring and apnea eventsare made worse in the supine position due to the weight of the tongueand other tissues pushing back on the airway. The subject awokerefreshed in the morning, reported no discomfort from the device andreported that he could have continued wearing the device indefinitely.At the conclusion of the experiment, the subject removed the device bypulling out device body 12 through the nostril using tether 14 in amatter of seconds. The example above shows that the present inventionsuccessfully addresses the shortcomings of the presently known art byproviding an air pathway through collapsed airway tissue during sleepwith a device that is safe, non-invasive, reversible, tolerable andeffective during both waking and sleeping hours.

It is appreciated that certain features of the invention, which are, forclarity, described in the context of separate embodiments, may also beprovided in combination in a single embodiment. For example, any devicebody, tethering, anchoring or delivery embodiment, configuration orscheme can be combined with each other to create a device that achievesall of the functions described herein. Conversely, various features ofthe invention, which are, for brevity, described in the context of asingle embodiment, may also be provided separately or in any suitablesubcombination.

Although the invention has been described in conjunction with specificembodiments thereof, it is evident that many alternatives, modificationsand variations will be apparent to those skilled in the art.Accordingly, it is intended to embrace all such alternatives,modifications and variations that fall within the spirit and broad scopeof the appended claims. All publications, patents and patentapplications mentioned in this specification are herein incorporated intheir entirety by reference into the specification, to the same extentas if each individual publication, patent or patent application wasspecifically and individually indicated to be incorporated herein byreference. In addition, citation or identification of any reference inthis application shall not be construed as an admission that suchreference is available as prior art to the present invention.

What is claimed is:
 1. A device for treating sleep disordered breathingcomprising a tether having a first end attached to an anchor, and asecond end attached to a device body configured as a sheet, an open orclosed tube, said tether being capable of suspending said device bodywithin a pharyngeal airway, said device body being designed andconfigured for maintaining patency of said airway or minimizingresistance to airflow during involuntary closure of said airway tissue.2. The device of claim 1, wherein said involuntary closure of saidairway is caused by collapse of airway tissue during sleep.
 3. Thedevice of claim 1, wherein said tube is configured capable of beingelastically closed by a radial force of about 30 grams or less.
 4. Thedevice of claim 1, wherein said tube is selected having a diameter of3-12 mm.
 5. The device of claim 1, wherein said tube is selected havinga length of 10-40 mm.
 6. The device of claim 1, wherein said suspendingminimizes contact between a surface of said device body and said airwaytissue when not maintaining patency of said airway or minimizingresistance to airflow during involuntary closure of said airway tissue.7. The device of claim 1, wherein at least some portion of said devicebody is comprised from a hydrophobic material.
 8. The device of claim 1,wherein at least some portion of said device body is comprised from ahydrogel.
 9. A method of treating sleep disordered breathing comprising:(a) inserting a device including a tether having a first end attached toa device body through a nostril; (b) suspending said device body withina pharyngeal airway, said device being designed and configured formaintaining patency of said airway or minimizing resistance to airflowduring sleep; and (c) anchoring said tether, thereby treating sleepdisordered breathing.
 10. The method of claim 9, wherein said devicebody is a sheet, an open or closed tube.
 11. The method of claim 9,wherein (a) is effected via an applicator attached to said device. 12.The method of claim 9, wherein said device body is suspended behind thesoft palate ending at or above the level of the uvula.
 13. The method ofclaim 9, wherein said tube is selected having a diameter of 3-12 mm. 14.The method of claim 9, wherein said tube is selected having a length of10-40 mm.